Fossilized Bees Reveal Climate Changes

Fossils from California’s La Brea Tar Pits keep supplying scientists with excellent material for studying the region’s past. Ancient animals, from mammoths to tiny insects, reveal facts about climate changes during the last Ice Age and help scientists understand the modern climate.

For millennia, natural tar that seeped from the ground in what is now southern California trapped large and small animals, preserving their fossils and providing scientists with a trove of specimens suitable for study.

Anna Holden, a researcher at the Page Museum in Los Angeles, is analyzing fossilized bees to learn about the ancient environment of the tar pits. In trying to reconstruct what the climate and local habitat were like, she said, “this bee offered kind of unprecedented information."

By exposing the fossils to a micro CT scanner, scientists discovered that the bee’s habitat was warmer than expected. They concluded that at the end of the Ice Age, about 11,500 years ago, this area was not covered with snow and ice, as previously thought.

Insects’ limited range – unlike that of the large mammals that came to La Brea from South America or across the land bridge now covered by the Bering Strait – allows the collection of detailed information about their immediate environment, Holden said.

“Insects have very specific life cycles, so they're just really good paleoecological indicators,” she said. “In other words, they're just very specific in their behavior, their habitats.”

Whoever collected the specimens in the 1970s did a good job of keeping records, Holden said. Comparing that data with current findings can reveal something about our future.

“Understanding past climate change is understanding current climate change,” she said. “Climate change is a big issue right now and insects are often really good indicators.”

Holden said her work may help today’s farmers fight the problem of collapsing bee populations, by switching over to bee species better adapted for the changing climate.

詞匯解析

reveal

難度：4星核心詞匯，屬常用3000詞

英漢解釋

vt.顯示；透露；揭示；展現(xiàn)

n.(外墻與門或窗之間的)窗側；門側；(汽車的)窗框

參考例句

用作及物動詞 (vt.)

Several withered trees on the sides of the road reveal the desolation here.

道路兩旁的幾棵枯木顯示出這里的荒涼。

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researcher

英漢解釋

n.研究人員

參考例句

用作名詞 (n.)

Researcher redefines the physics of photons.

研究人員重新定義光子物理學。

Vendors would give public credit to the researcher.

銷售商則將給予研究人員公開好評。

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respond

難度：4星核心詞匯，屬常用3000詞

英漢解釋

v.回答；響應；反應；反應靈敏；反響

n.[建]壁聯(lián)；[宗]應唱圣歌

參考例句

用作動詞 (v.)

I invited her to dinner but she did not respond.

我請她吃晚飯，但她未作回答。

The professor lectured with a beaming countenance, but the students didn't respond much, only agreeing with what he said.

教授講得眉飛色舞，學生們卻沒有太大的反響，只是隨聲應和。

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limited

難度：5星基本詞匯，屬常用1000詞

英漢解釋

adj.有限的；被限制的

動詞limit的過去式和過去分詞形式.

參考例句

用作形容詞 (adj.)

We had only limited communion with the natives.

我們與本地人的交往有限。

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collection

難度：4星核心詞匯，屬常用3000詞

英漢解釋

n.收集；收取，托收；聚集；收藏品；募捐

參考例句

用作名詞 (n.)

The collection of these stamps took ten years.

收集這些郵票花了十年時間。

The firm contributed 10,000 to the collection.

公司拿出10,000元做為募捐。

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immediate

難度：3星常用詞匯，屬常用6000詞

英漢解釋

adj.直接的；最接近的；立即的；目前的

參考例句

用作形容詞 (adj.)

The evidence has no immediate bearing on the case.

該證據(jù)與本案無直接關系。

Today's immediate problem is one of distribution of both food and income.

目前面臨的緊迫問題是食物分配和收入分配問題。

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fleet

難度：4星核心詞匯，屬常用3000詞

英漢解釋

n.艦隊；船隊；機群

adj.快速的；敏捷的；短暫的

vt.使（時間）飛逝

vi.疾飛；掠過；逐漸消失

參考例句

用作名詞 (n.)

The general ordered the fleet to remain where they were and wait for the further instructions.

將軍命令艦隊原地待命。

用作形容詞 (adj.)

That is a fleet horse.

那是一匹快馬。

用作及物動詞 (vt.)

On board the ship I fleet time by read detective story.

在船上我讀偵探小說，借以消磨時間。

用作不及物動詞 (vi.)

A plane fleeted over the top of the hill.

一架飛機掠過山頂。

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current

難度：5星基本詞匯，屬常用1000詞

英漢解釋

n.趨勢；(水、氣、電)流

adj.現(xiàn)在的；流通的

參考例句

用作名詞 (n.)

Nothing disturbs the peaceful current of life in the village.

沒有任何事干擾村里一向平靜的生活.

用作形容詞 (adj.)

How long will she keep her current job?

她現(xiàn)在這份工作能維持多久?

 

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